Blowback and recoil aren't even close to the same thing.  

In a blowback operated system, the breech isn't locked.  The weight of the slide or bolt and the resistance from the spring is the only thing holding it closed until pressure subsides enough to be safe to operate.  Obviously if you want to use this on a higher pressure system you need to increase bolt mass and/or spring tension.  Blowback also has the disadvantage of causing heavier felt recoil than other systems.  Its only real pro is that it's cheap.

There are two types of recoil operated, long and short.  Most major caliber pistols and a lot of the small .380s around today use short recoil.  Short recoil is when the barrel and slide are briefly locked together.  They travel rearward, the barrel then unlocks and stops.  Inertia keeps the slide moving rearward, recoil spring moves it back forward where it picks up the barrel, forcing it forward as well and locking the two back together.  The Browning system is the most common, seen in the 1911, Sigs, Glocks, HiPower, etc.  The Beretta 92 and Walther P38 use a dropping locking block.  Rotating barrel is another method that's not quite as common.  Short recoil allows you to use a lighter recoiling mass thereby reducing felt recoil.   In a long recoil system, the barrel and slide/bolt are locked together for the entire rearward travel.  Once they reach the end of their travel the bolt is locked to the rear and the barrel is free to return forward.  Upon returning forward, the barrel unlocks the bolt which then also returns forward.

7.5" AR pic thread?  

I know the difference Josh, my apologies for using recoil instead of blowback in the first post.


What I'm talking about is just using an in production 45acp bolt with a 22tcm barrel and appropriate weight recoil spring.



A gas operated  semi auto in any pistol caliber short of the bigger magnums seems like overkill to me.

Gas operated PCCs have much softer recoil.  Ron has a video of him doing full auto mag dumps out of his .45 DI, impressively controllable.

Very nice, sir.  Could you tell me more about that fore end and muzzle device?  Is that a Noveske KX5?

That is a reason I can see spending money on GO pistol caliber AR upper.

Of course, I'd have to get the money for a FA M16 lower first..............

All seems like a great idea until you shoot one without earpro indoors.  

You literally cannot help but hesitate to squeeze the trigger a second time.  

I've shot my 7.5" once without without a suppressor or hearing protection. I will never do that again.

What?

I shot my 7.5 outside, but in between my shed and garage, which are about 15 feet apart. The concussion made me crosseyed.

In an HD scenario I would not select that item first. However I am two stamps away from Honey Badger clone territory.  Both due in this week.

Huh? Did you say something?

100 yards, self defense, stopped reading, wut.

my pistol is pretty accurate. I keep 6 inch groups, standing position, between 25-50yards. I'm happy with it.